fix(badge): faithful 3d masthead sphere with true 360 yaw spin

[Flotapponnier]

Summary

• Badge SVG logo now replicates the real masthead 3D sphere (site-logo-3d.tsx texture geometry): dark skin, C-ring + grey corner markers, limb darkening, specular highlight
• Replaces the scaleX coin-flip with a true 360 yaw: the mark slides to the right limb with cosine foreshortening, hides behind the sphere, re-enters from the left limb (3.2s loop, reduced-motion freezes front pose)
• Background-colored cover ring hides mark overshoot past the silhouette (clip-path on animated content is unreliable in some img renderers)

Test plan

• Rendered front + intermediate yaw poses in headless Chrome at 4x
• Full-size badge render with rank/title/scope text
• tsc + bun test pass